1. Field of the Invention
This invention is directed to extracts of plant species of the genus Neriuim which are useful in treating cell-proliferative diseases in animals. In addition, the invention is directed to methods of preparing these extracts and methods of using these extracts for the diagnosis and amelioration of cell-proliferative diseases in animals.
2. Description of the Background Art
Plants of the genus Nerium are members of the Apocynaceae family. These plants are native to Asia and the Mediterranean region and have been introduced as ornamental shrubs to most countries in Africa, South America and the southern United States. Within this genus, Nerium oleander is probably the best known.
This plant, also known as rose laurel, adelfa, and rosenlorbeer is toxic in its natural state and has caused deaths among humans, as well as household pets and farm animals. One leaf of oleander is considered potentially lethal to humans. Accidental poisoning in humans has occurred from chewing the flowers and from eating meat cooked over oleander branches or foods stirred with oleander stems. Smoke derived from the burning wood and leaves and honey manufactured from the nectar of oleander blossoms have been considered potentially dangerous in man.
Symptoms of poisoning, after a latent period of several hours, include severe abodminal pain, violent vomiting, cyanosis, tachycardia, hypotension, and hypothermia. In severe cases, in addition to these systems, an individual may exhibit drowsiness, mydriasis, vertigo, bloody diarrhea, cardiac irregularities, comma, respiratory paralysis, and death. In man, contact dermatitis has also been reported.
The presence of glycosides in a crude water extract from leaves of N. oleander has been studied for its effect on mitosis of meristematic root tip cells in Allium cepa (Tarkowska, Acta Societatis Botanicorium Poloniae:40: 624, 1971).
The known active components of the oleander are primarily oleandrin, neriine and other digitoxin-like glycosides. These glycosides are similar in physiologic action to digitalis and have apparently been used clinically in the treatment of human heart disease as a substitute for digitalis. However, in spite of the fact that the orleander can serve as a basis for these cardiac glycosides, it has never been scientifically demonstrated that extracts of this plant could be used to treat cell-proliferative diseases in animals.